CHARLOTTE, N.C. — After a week of minor signings, the Carolina Panthers made their first significant move in free agency today by coming to terms with linebacker Landon Johnson on a three-year deal.

Johnson spent the past four seasons in Cincinnati, where he started at all three linebacker spots in the same 4-3 defensive scheme the Panthers use. Johnson racked up 112 and 109 tackles in the past two years and could unseat Na'il Diggs as Carolina's starter at outside linebacker.

Johnson visited Carolina on Thursday and agreed to the deal Friday morning.

"The city, the team and the coaches all made a tremendous impression on him," said Andy Simms, Johnson's agent. "It's a tremendous opportunity for him to further his career and get a chance to play where he can help the team."

Free agency started last Friday and the Panthers had been quiet with what's been described as a weak pool of players available. Carolina signed three players — guard Keydrick Vincent, defensive lineman Tyler Brayton and cornerback Ricardo Colclough — but they aren't expected to be immediate impact players.

Johnson could be. A third-round pick from Purdue, the 6-foot-2, 232-pound Johnson has not missed a game in four seasons and started every game the last two years.

Johnson turns 27 next week and could take over at weakside linebacker for the 29-year-old Diggs, who signed a contract extension at the end of last season.

Linebacker looks to be an area of strength for Carolina. Jon Beason became the starter at middle linebacker last season and led the team in tackles. Thomas Davis has improved as the starter at the other outside linebacker spot.

The Panthers still have several holes to fill, notably on the defensive and offensive lines and at safety and receiver.

Johnson is the third starter to leave the Bengals in free agency. Defensive end Justin Smith went to San Francisco and free safety Madieu Williams signed with Minnesota.